The Streptococcus mutans genes coding for sucrose metabolism as well as interaction with glucans will be cloned into Escherichia coli utilizing recombinant DNA techniques. The transformed colonies will be utilized to investigate the role of the gene products in the cariogenic properties of S. mutans. Transformed minicells of E. coli containing the genes for glucosyltransferase will be utilized to characterize the isoenzymes of this enzyme and investigate the mechanisms of synthesis and secretion of the exoenzyme. Mutants of these clones altered in phospholipid biosynthesis will be sought to investigate the role of phospholipid-enzyme interactions in the secretory process. The isolation of clones containing either the extracellular or intracellular invertase activities will be utilized to examine the relationship between these two activities. Amplifiable clones containing the glucan receptor of S. mutans will be utilized to isolate and characterize these molecules. Purified cell surface components of S. mutans will be incorporated into liposomes in order to investigate the role of these molecules in attachment to tooth surfaces. Liposome-glucosyltransferase-glucan receptor complexes will also be constructed to examine the role of these molecules in surcrose-dependent colonization.